• Mycobiology
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• 제50권5호
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• pp.302-316
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• 2022

Many Apiospora species have been isolated from bamboo plants - to date, 34 bambusicolous Apiospora species have been recorded. They are known as saprophytes, endophytes, and plant pathogens. In this study, 242 bambusicolous Apiospora were isolated from various bamboo materials (branches, culms, leaves, roots, and shoots) and examined using DNA sequence similarity based on the internal transcribed spacer, 28S large subunit ribosomal RNA gene, translation elongation factor 1-alpha, and beta-tubulin regions. Nine Apiospora species (Ap. arundinis, Ap. camelliae-sinensis, Ap. hysterina, Ap. lageniformis sp. nov., Ap. paraphaeosperma, Ap. pseudohyphopodii sp. nov., Ap. rasikravindrae, Ap. saccharicola, and Ap. sargassi) were identified via molecular analysis. Moreover, the highest diversity of Apiospora was found in culms, and the most abundant species was Ap. arundinis. Among the nine Apiospora species, two (Ap. hysterina and Ap. paraphaeosperma) were unrecorded in Korea, and the other two species (Ap. lageniformis sp. nov. and Ap. pseudohyphopodii sp. nov.) were potentially novel species. Here, we describe the diversity of bambusicolous Apiospora species in bamboo organs, construct a multi-locus phylogenetic tree, and delineate morphological features of new bambusicolous Apiospora in Korea.

• Animal Systematics, Evolution and Diversity
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• 제39권4호
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• pp.264-271
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• 2023

The edible jellyfish Rhopilema esculentum occurs in waters throughout northeastern Asia, including in Korea, China, and Japan. In Korean waters, R. esculentum has appeared in two regions (Gangwha and Muan). Based on the appearance of young medusae and coastal distribution records, these two regions may be key R. esculentum breeding sites. In the present study, we investigate and compare the genetic structure of R. esculentum in the two regions using mitochondrial sequences (16S ribosomal RNA and cytochrome c oxidase subunit I). The genetic diversity of the R. esculentum population at Ganghwa exceeded that of the population at Muan. Despite considerable geographic separation (400 km) between the two regions(Gangwha and Muan), our haplotype network suggests that the Gangwha and Muan populations of R. esculentum are related. The simple and monotonous genetic structure of the Muan population shows that R. esculentum emergence is relatively recent. In contrast, the Gangwha population shows evolution. Moreover, jellyfish of the Gangwha population are genetically diverse and remain constant despite environmental fluctuations in the Han River. The Gangwha area is considered to be the old origin of R. esculentum in Korea.

• Mycobiology
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• 제51권5호
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• pp.300-312
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• 2023

Hydnum is a genus of ectomycorrhizal fungi belonging to the Hydnaceae family. It is widely distributed across different regions of the world, including North America, Europe, and Asia; however, some of them showed disjunct distributions. In recent years, with the integration of molecular techniques, the taxonomy and classification of Hydnum have undergone several revisions and advancements. However, these changes have not yet been applied in the Republic of Korea. In this study, we conducted an integrated analysis combining the morphological and molecular analyses of 30 specimens collected over a period of approximately 10 years in the Republic of Korea. For molecular analysis, the sequence data of the internal transcribed spacer (ITS) region, the large subunit of nuclear ribosomal RNA gene (nrLSU), and a portion of translation elongation factor 1-a (TEF1) were employed as molecular markers. Through this study, we identified eight species that had previously not been reported to occur in the Republic of Korea, including one new species, Hydnum paucispinum. A taxonomic key and detailed descriptions of the eight Hydnum species are provided in this study.

• 한국균학회지
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• 제51권4호
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• pp.491-504
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• 2023

To explore fungal diversity in orchard soil where fire-blighted apple trees are buried, we collected soil samples from apple orchards in Chungju, Korea. Fungal isolates were obtained from DG18 agar and identified at the species level based on morphological features and phylogenetic analyses. The colony characteristics and microstructures were examined using a light microscope and a scanning electron microscope after culturing on potato dextrose agar (PDA), malt extract agar (MEA), Czapek yeast agar (CYA), and oatmeal agar (OA) The PCR-amplified products of the ITS1-5.8S-ITS2 region and 28S large subunit of the nuclear ribosomal RNA gene, as well as partial sequences of the β-tubulin, calmodulin, and translation elongation factor 1-α genes were sequenced and analyzed phylogenetically. Seven previously unknown fungal species were explored in Korea. All samples, including Aspergillus aureolatus, Botryotrichum atrogriseum, Dactylonectria novozelandica, Fusarium denticulatum, Paecilomyces tabacinus, Sarcopodium tibetense and Talaromyces stollii, had ascomycetes. Herein, we report their descriptions and features.

• 한국자원식물학회지
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• 제19권1호
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• pp.54-58
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• 2006

한국, 중국, 러시아에서 자생하고 있는 가시오갈피에 대한 유전적 유연관계를 파악하기 위해 ITS (internal transcribed spacer)의 염기서열을 분석하였다. Universal primer를 사용하여 PCR로 증폭시킨 후 염기서열을 결정한 결과 ITS의 길이는 162 bp의 5.8S rRNA 유전자를 포함하여 한국산과 중국산은 608 bp 그리고 러시아산은 611 bp로 나타났다. ITS영역의 G+C 함량은 한국산과 중국산이 60.20%이고 러시아산이 60.06%였다. 한국산과 중국산의 ITS영역은 100% 동일하였으며, 러시아산은 한국산과 비교했을 때 3 bp의 염기삽입과 2 bp의 염기치환이 존재하여 99.2%의 상동성을 나타내었다. 따라서 한국산 가시오갈피는 러시아산보다 중국산과 유전적 유연관계가 더 가까운 것으로 추정된다. 또한 동일 속내에서는 오갈피나무보다는 음나무와 ITS 염기서열이 유사한 것으로 나타났다.

• 한국식품저장유통학회지
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• 제21권2호
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• pp.286-293
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• 2014

본 연구에서는 식품산업에 적용 가능한 amylase의 발굴을 위하여 된장으로부터 amylase를 생산하는 균주를 분리하였고, 분리된 미생물들의 동정을 통하여 GRAS 미생물로 부터 생산되는 amylase에 대한 효소 특성을 규명하였다. 그 결과 균주 유래 16S ribosomal RNA 유전자 염기서열에서 B. subtilis로 동정되어 본 균주를B. subtilis CBD2로 명명하였다. B. subtilis CBD2 균주의 생육에 미치는 배지 성분에 대한 특성을 검토한 결과 본 균주는 pH 7.0, NaCl 3%, glucose 10%에서 가장 높은 균 생육 특성을 나타내었다. 그리고 본 균주의 amylase 생산에 미치는 탄소원의 영향을 검토한 결과, 본 균주는 soluble starch, corn starch, maize amylopectin 및 wheat starch 중에서 soluble starch를 탄소원으로 사용하였을 때 가장 높은 amylase 생산성을 나타내었다. B. subtilis CBD2유래 amylase의 활성에 미치는 반응조건을 검토한 결과 본 균주 유래 amylase는 pH 8.0 그리고 $50^{\circ}C$에서 가장 높은 효소 활성을 나타내었으며 기질특이성에 대한 검토에서는 corn starch>wheat starch>soluble starch>maize amylopectin 순으로 효소 활성을 나타내었다. B. subtilis CBD2가 생성하는 amylase 효소와 corn starch 기질 반응에 대한 전분 분해능 및 당 생성율 변화에서는 24시간에서 가장 높은 전분 분해능 및 당 생성율을 나타내어 corn starch를 이용한 효소 반응은 24시간이 가장 적절함을 확인할 수 있었다. 따라서 본 연구에서 분리된 균주는 GRAS 미생물인B. subtilis이었으며 본 균주 유래의 amylase 특성을 활용한다면 향 후 식품산업에 있어서 전분 분해 관련 분야에 유용하게 이용될 것으로 기대되어진다.

• 아시안잔디학회지
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• 제21권2호
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• pp.147-154
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• 2007

2004년 3월에 전라북도에 위치한 한 골프장의 켄터키 블루그래스와 퍼레니얼 라이그래스에 설부병이 발병되었다. 감염된 잔디잎들은 서로 엉켜저 매트화 되고, 흰색에서 회백색의 균사체들로 덮여있었다. 균핵들은 잔디의 엽신, 엽초 및 관부 위에 형성되어 있었다. 이병 잎으로부터 분리된 곰팡이는 직경이 1.4 mm 미만의 밝은 핑크에서 갈색의 불규칙한 모양의 균핵과 꺽쇠연결체, 흰색의 균사체 등을 형성하여 Typhula incarnata와 같은 특징을 보였다. 분리된 T. incarnata의 균사생육 적온은 $5{\sim}15^{\circ}C$이었다. 원인균의 ribosomal RNA IST1의 부분 염기서열은 GeneBank database에 등록된 T. incarnata의 부분 염기서열과 91%로의 상동성을 보여 T. incarnata로 동정되었다. 실내 약제방제 시험결과 14개 살균제 중 iprodione, tebuconazole, polyoxin D, flutolanil, hexaconazole, tolclofos-methyl, fosetyl-Al, mepronil, pencycuron+ tebuconazole 및 fenarimol 살균제들은 추천농도에서 완전하게 균생장을 억제하였다. 포장시험에서, 이들 살균제와 thifluzamide와 thiram과 같은 살균제들은 다소 방제효능의 정도 차이는 있지만 효과적으로 잔디 설부병을 방제하였다.

• Parasites, Hosts and Diseases
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• 제55권6호
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• pp.601-606
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• 2017

Cystoisospora is responsible for morbidity in immunocompromised patients. PCR is sensitive for diagnosing Cystoisospora; however, it needs reevaluation for differential molecular diagnosis of cystoisosporiasis. We aimed at evaluating melting curve analysis (MCA) after real-time PCR (qPCR) in diagnosis and genotyping of Cystoisospora as an alternative to conventional PCR. We included 293 diarrheic stool samples of patients attending the Department of Clinical Oncology and Nuclear Medicine of Cairo University Hospitals, Egypt. Samples were subjected to microscopy, nested PCR (nPCR), and qPCR targeting the internal transcribed spacer 2 region (ITS2) of the ribosomal RNA (r RNA) gene followed by melting temperatures ($T_ms$) analysis and comparing the results to PCR-RFLP banding patterns. Using microscopy and ITS2-nPCR, 3.1% and 5.8% of cases were Cystoisospora positive, respectively, while 10.9% were positive using qPCR. Genotyping of Cystoisospora by qPCR-MCA revealed 2 genotypes. These genotypes matched with 2 distinct melting peaks with specified $T_ms$ at $85.8^{\circ}C$ and $88.6^{\circ}C$, which indicated genetic variation among Cystoisospora isolates in Egypt. Genotype II proved to be more prevalent (65.6%). HIV-related Kaposi sarcoma and leukemic patients harbored both genotypes with a tendency to genotype II. Genotype I was more prevalent in lymphomas and mammary gland tumors while colorectal and hepatocellular tumors harbored genotype II suggesting that this genotype might be responsible for the development of cystoisosporiasis in immunocompromised patients. Direct reliable identification and differentiation of Cystoisospora species could be established using $qPCR-T_ms$ analysis which is useful for rapid detection and screening of Cystoisospora genotypes principally in high risk groups.

• Parasites, Hosts and Diseases
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• 제53권1호
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• pp.13-19
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• 2015

Blastocystis sp. is a common zoonotic intestinal protozoa which has been classified into 17 subtypes (STs). A cross-sectional study was conducted to determine the prevalence and subtype distribution of Blastocystis in villagers living on the Thai-Myanmar border, where the risk of parasitic infection is high. A total of 207 stool samples were collected and DNA was extracted. PCR and sequencing using primers targeting small-subunit ribosomal RNA (SSU rRNA) gene were performed. The prevalence of Blastocystis infection was 37.2% (77/207). ST3 (19.8%; 41/207) was the predominant subtype, followed by ST1 (11.6%; 24/207), ST2 (5.3%; 11/207), and ST4 (0.5%; 1/207). A phylogenetic tree was reconstructed using the maximum likelihood (ML) method based on the Hasegawa-Kishino-Yano + G + I model. The percentage of bootstrapped trees in which the associated taxa clustered together was relatively high. Some sequences of Blastocystis positive samples (TK18, 39, 46, 71, and 90) were closely related to animals (pig and cattle) indicating zoonotic risks. Therefore, proper health education in parasitic prevention for the villagers should be promoted to improve their personal hygiene. Further longitudinal studies are required to monitor the prevalence of parasitic infections after providing health education and to investigate Blastocystis ST in animals living in these villages.

• 상하수도학회지
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• 제29권1호
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• pp.47-55
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• 2015

Recently, the production of taste and odor (T&O) compounds is a common problem in water industry. Geosmin is one of the T&O components in drinking water. However, geosmin is hardly eliminated through the conventional water treatment systems. Among various advanced processes capable of removing geosmin, adsorption process using granular activated carbon (GAC) is the most commonly used process. As time passes, however GAC process changes into biological activated carbon (BAC) process. There is little information on the BAC process in the literature. In this study, we isolated and identified microorganisms existing within various BAC processes. The microbial concentrations of BAC processes examined were $3.5{\times}10^5$ colony forming units (CFU/g), $2.2{\times}10^6CFU/g$ and $7.0{\times}10^5CFU/g$ in the Seongnam plant, Goyang plant and Goryeong pilot plant, respectively. The dominant bacterial species were found to be Bradyrhizobium japonicum, Novosphingobium rosa and Afipia broomeae in each plants. Removal efficiencies of $3{\mu}g/L$ geosmin by the dominant species were 36.1%, 36.5% and 34.3% in mineral salts medium(MSM) where geosmin was a sole carbon source.